The present invention relates to a method of manufacturing a flat-panel display device including a process for pasting a light-control tape in an elongated shape, which serves to control light transmittance, onto a display cell (display panel proper), in a flat-panel display device such as a liquid-crystal display device.
A flat-panel display device of a light-transmissive mode, such as a liquid-crystal display device, has a back light on a rear side of the display cell in order to irradiate the display cell. On a rear main face of the display cell, a light-control tape is pasted, in order to prevent light from the back light and the like from leaking through non-displaying area outside the viewing area (a real or effective displaying area) of the display cell to reach a viewer.
Steps of pasting the light-control tape are, for example, as follows.
After carrying out an outer lead bonding (OLB) process for connecting tape carrier packages (TCPs) onto peripheral portion on the display cell, there is carried out a soldering process for soldering the TCPs onto a wiring board. After the soldering process, with the rear main face of the display cell being kept facing upside, an operator manually pastes the light-control tape on the rear main face.
Such manner of pasting the light-control tape poses a problem that accuracy of the pasting varies with the operator and a problem that a complicated operation is required for the operator. Particularly, in respect of the accuracy, length of the light-control tape have to be longer than that of a polarizer stuck on the rear main face of the display cell while the light-control tape have to be prevented from extruding beyond outline of the glass substrate. Further, it is necessary that a gap between the light-control tape and the polarizer is made equal to or smaller than 1 mm. These require a very difficult operation.
Hence, in view of the above-described problems, it is an object of the invention to provide a method of manufacturing a flat-panel display device capable of pasting the light-control tape to the display cell easily and accurately.
BRIEF SUMMARY OF THE INVENTION
According to an aspect of the invention, a method of manufacturing a flat-panel display device includes steps for attaching an elongate light-control tape onto a non-displaying area of a display cell (display panel proper), so as to control (especially, shield or reflect) light transumittance or light incident upon the non-displaying area, said display panel cell being light-transmissive and arranged with a plurality of pixels in a displaying area, said steps for attaching comprising: a step of determining a start position for pasting a start end of the light-control tape on the display cell; a step of taking out the start end of the light-control tape by drawing to peel a release sheet covering a downward-facing adhesive face of the light-control tape, said release sheet being drawn reverseward to a direction of the taking out of the start end; a step of positioning the start end of the light-control tape to the start position; a step of pressing the start end of the light-control tape onto the start position by a rotatable press roller; a step of continuously pasting the light-control tape onto the display cell by moving the display cell in the direction of the taking out of the start end while keeping the light-control tape being pressed by the press roller; a step of cutting the light-control tape when the light-control tape is pasted by a predetermined length; and a step of completing of pasting a cut piece of the light-control tape onto the display cell, by use of the press roller, up to a cut end of the light-control tape.
According to another aspect of the invention, said display cell is of a liquid crystal display and has a polarizer at a main surface thereof; said step of determining a start position further comprising a step of width-wise positioning of the light-control tape in respect of an edge of the polarizer.
According to a still another aspect of the invention, the method further comprises a step of attaching tape carrier packages onto said display cell by compression bonding procedure, before said series of steps for pasting.
According to further aspect of the invention, the method further comprises a step of soldering for connecting the tape carrier packages with a wiring board after said step of attaching onto said display cell, before said series of steps for pasting.
An explanation will be given of a series of steps for pasting the light-control tape in the elongated shape to the display cell, in accordance with invention-wise method of manufacturing the flat-panel display device.
In the first step, the pasting position for pasting the start end of the light-control tape to the display cell is determined or confirmed. In this step, width-wise positioning of the light-control tape is carried out based on an edge of the polarizer, which is already stuck on the display cell.
In the second step, the start end of the light-control tape is taken out by drawing to peel a release sheet covering a downward-facing adhesive face of the light-control tape, said release sheet being drawn reverseward to a direction of the taking out of the start end.
In the third step, the start end of the light-control tape is positioned to the pasting-start position.
In the fourth step, the start end of the light-control tape is pressed onto the pasting-start position by the rotatable press roller.
In the fifth step, the light-control tape is continuously pasted onto the display cell by moving the display cell in the direction of the taking out of the start end while keeping the light-control tape being pressed by the press roller.
In the sixth step, the light-control tape is cut at a predetermined position when the light-control tape is pasted by a predetermined length.
In the seventh step, a cut piece of the light-control tape is further pasted onto the display cell by use of the press roller, up to a cut end of the light-control tape.
By using such a manufacturing method, the light-control tape can be pasted onto the display cell easily and accurately without using manual labor